$column-total-size = 24

loop-column-size($class, $size)
  .{$class}-{$size}
    width round(percentage($size / $column-total-size), 7)
  if $size > 0
    loop-column-size($class, $size - 1)

loop-column-size($col-prefix, $column-total-size)

.{$row-prefix}
  overflow hidden
  &:after
    content ''
    clear both

.{$row-prefix}, .{$row-prefix}:after
  display block

.{$col-prefix}
  float left
  display block
  box-sizing border-box
